Bone mineral density and functional measures in patients with arthrogryposis

Periodic health evaluation in Para athletes: a position statement based on expert consensus

Para athletes present a broad range of sports-related injuries and illnesses, frequently encountering barriers when accessing healthcare services. The periodic health evaluation (PHE) is a valuable tool for continuously monitoring athletes' health, screening for health conditions, assisting in the surveillance of health problems by establishing baseline information and identifying barriers to athlete's performance. This position statement aims to guide sports healthcare providers in the PHE for Para athletes across key impairment categories: intellectual, musculoskeletal, neurological and vision. A panel of 15 international experts, including epidemiologists, physiotherapists, optometrists and physicians with expertise in Para athlete health, convened via videoconferences to discuss the position statement's purpose, methods and themes. They formed working groups to address clinical, cardiorespiratory, neuromusculoskeletal, nutritional status, mental and sleep health, concussion and female Para athlete health assessment considerations. The PHE's effectiveness lies in its comprehensive approach. Health history review can provide insights into factors impacting Para athlete health, inform physical assessments and help healthcare providers understand each athlete's needs. During the PHE, considerations should encompass the specific requirements of the sport modality and the impairment itself. These evaluations can help mitigate the common tendency of Para athletes to under-report health issues. They also enable early interventions tailored to the athlete's health history. Moreover, the PHE serves as an opportunity to educate Para athletes on preventive strategies that can be integrated into their training routines, enhancing their performance and overall health. This position statement can potentially enhance clinical translation into practice and improve the healthcare quality for Para athletes.

Bone mineral density in adults with arthrogryposis multiplex congenita: a retrospective cohort analysis

The primary objective of this study was to evaluate the prevalence of low femoral and lumbar spine bone mineral density (BMD) in adults with arthrogryposis multiplex congenita (AMC). We performed a retrospective cohort analysis of adults with AMC who were enrolled in the French Reference Center for AMC and in the Pediatric and Adult Registry for Arthrogryposis (PARART, NCT05673265). Patients who had undergone dual-energy X-ray absorptiometry (DXA) and/or vitamin D testing were included in the analysis. Fifty-one patients (mean age, 32.9 ± 12.6 years) were included; 46 had undergone DXA. Thirty-two (32/51, 62.7%) patients had Amyoplasia, and 19 (19/51, 37.3%) had other types of AMC (18 distal arthrogryposis, 1 Larsen). Six patients (6/42, 14.3%) had a lumbar BMD Z score less than - 2. The mean lumbar spine Z score (- 0.03 ± 1.6) was not significantly lower than the expected BMD Z score in the general population. Nine (9/40, 22.5%) and 10 (10/40, 25.0%) patients had femoral neck and total hip BMD Z scores less than - 2, respectively. The mean femoral neck (- 1.1 ± 1.1) and total hip (- 1.2 ± 1.2) BMD Z scores in patients with AMC were significantly lower than expected in the general population (p < 0.001). Femoral neck BMD correlated with height (rs = 0.39, p = 0.01), age (rs = - 0.315, p = 0.48); total hip BMD correlated with height (rs = 0.331, p = 0.04) and calcium levels (rs = 0.41, p = 0.04). Twenty-five patients (25/51, 49.0%) reported 39 fractures. Thirty-one (31/36, 86.1%) patients had 25-hydroxyvitamin D levels less than 75 nmol/l, and 6 (6/36, 16.7%) had 25-hydroxyvitamin D levels less than 75 nmol/l. Adults with AMC had lower hip BMD than expected for their age, and they more frequently showed vitamin D insufficiency. Screening for low BMD by DXA and adding vitamin D supplementation when vitamin D status is insufficient should be considered in adults with AMC, especially if there is a history of falls or fractures.

Current rehabilitation practice for the evaluation and treatment of children with arthrogryposis: an international survey

PURPOSE

To describe the current practices in rehabilitation for the evaluation and treatment of children with arthrogryposis multiplex congenita (AMC).

MATERIALS AND METHODS

Rehabilitation practitioners worldwide with at least 2 years of experience with AMC were invited to complete an electronic survey on the evaluations and treatments used with children with AMC within five areas: muscle and joint function, self-care, mobility, pain, participation and psychosocial wellbeing.

RESULTS

Sixty five participants from nine countries completed the survey. Participants completed the sections applicable to their practice. Number of participants within each area varied between 24 and 53. Over 80% of participants used non-standardized evaluations across areas while <50% used patient-reported or standardized measures. Stretching of upper and lower limbs was reported by >80% across ages and clinical presentation severity. Strengthening reported by >70% was mainly used among children >3 years old with less severe contractures. Other interventions used across areas included orthotics (>70%), positioning (>80%), activity-based training (>80%), assistive devices for self-care (>50%) and mobility (>80%), and energy conservation (>70%). Over 70% of participants were involved in perioperative rehabilitation.

CONCLUSION

Knowledge of current pediatric rehabilitation practice in AMC, together with empirical evidence, may guide clinical decision-making and identify avenues for future research.

Characterizing Pain Among Adolescents and Young Adults With Arthrogryposis Multiplex Congenita

PURPOSE

Primary study objectives were to ( a ) characterize pain and explore differences between adolescents and adults with arthrogryposis multiplex congenita (AMC) and ( b ) evaluate associations between pain-related outcomes and mobility.

METHODS

People who can walk and with AMC completed pain-related questionnaires.

RESULTS

Sixty-three participants (28 adolescents and 35 young adults) were recruited. Pain was reported in the past week by 81% of participants; intensity ratings were similar between age groups. Per the McGill Pain Questionnaire, pain severity was significantly lower among adolescents. Adults had a greater number of painful regions compared with adolescents. Greater 7-day average pain intensity, McGill Pain Questionnaire scores, and number of painful regions were associated with reduced functional mobility.

CONCLUSIONS

As most adolescents and young adults with AMC have at least mild pain, and pain is associated with mobility, future longitudinal investigations of pain and its functional consequences are warranted.

Expert guidance for the rehabilitation of children with arthrogryposis: protocol using an integrated knowledge translation approach

BACKGROUND

Arthrogryposis multiplex congenita (AMC) is a group of rare congenital disorders characterized by multiple joint contractures present at birth. Contractures can affect different body areas and impact activities of daily living, mobility and participation. Although early rehabilitation is crucial to promote autonomy and participation in children with AMC, empirical evidence to inform best practice is scarce and clinical expertise hard to develop due to the rarity of AMC. Preliminary research involving stakeholders in AMC (youth with AMC, parents, and clinicians) identified priorities in pediatric rehabilitation. Scoping reviews on these priorities showed a lack of high quality evidence related to rehabilitation in AMC. The objective of this project is to provide rehabilitation expert guidance on the assessment and treatment of children with AMC in the areas of muscle and joint function, pain, mobility and self-care, participation and psychosocial wellbeing.

METHODS

An integrated knowledge translation approach will be used throughout the project. Current rehabilitation practices in AMC will be identified using a clinician survey. Using the Grading of Recommendations, Assessment, Development and Evaluations framework (GRADE) approach, a panel of interdisciplinary expert clinicians, patient and family representatives, and researchers will develop expert guidance on the assessment and treatment for pediatric AMC rehabilitation based on findings from the scoping reviews and survey results. Consensus on the guidance statements will be sought using a modified Delphi process with a wider panel of international AMC experts, and statements appraised using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) tool. Theoretical facilitators and barriers toward implementing clinical guidance into practice will be identified among rehabilitation clinicians and managers to inform the design of dissemination and implementation strategies.

DISCUSSION

This multi-phase project will provide healthcare users and providers with research-based, expert guidance for the rehabilitation of children with AMC and will contribute to family-centered practice.

Psychosocial wellbeing among children and adults with arthrogryposis: a scoping review

BACKGROUND

Arthrogryposis multiplex congenita (AMC) is a group of congenital conditions characterized by joint contractures in two or more body areas. Management of AMC starts early in life and focuses on improving mobility and function through intensive rehabilitation and surgical interventions. Psychosocial wellbeing is an important determinant of health and the psychosocial experience of individuals with AMC should be considered in the management of this condition. The aim of this scoping review was to explore what is known about the psychosocial wellbeing of children and adults with AMC, to identify the outcome measures used and to explore the factors associated with psychosocial outcomes in this population.

METHODS

A comprehensive search in four databases was conducted. Articles discussing psychosocial outcomes and outcome measures used with children or adults with AMC were included. Data on the measures used, psychosocial outcomes, and factors associated with psychosocial outcomes, were extracted and analyzed descriptively and synthesized narratively.

RESULTS

Seventeen articles were included in this scoping review, ten including the pediatric population, six including adults and one article including both children and adults with AMC. The most commonly used outcome measures were the PODCI in the pediatric studies, and the SF-36 in studies on adults. In the pediatric studies, psychosocial outcomes were often secondary, compared to the studies on adults. Results showed that in both children and adults, psychosocial outcomes are comparable with the levels of the general population. Qualitative studies reflected the affective needs of this population and issues with emotional wellbeing. Factors such as fatigue and pain were associated with poorer psychosocial outcomes in adults with an impact on social relationships, intimacy and family planning.

CONCLUSION

Validated outcome measures, qualitative approaches and longitudinal studies are needed to better understand the psychosocial outcomes in AMC over time. Psychosocial support should be part of the multidisciplinary management of AMC throughout the lifespan.

Patient-Reported Outcome Measurement Information System (PROMIS) Scores in Pediatric Patients With Arthrogryposis

BACKGROUND

Arthrogryposis multiplex congenita (AMC) is a clinical term that is used to describe congenital contractures that lead to childhood deformities. Treatment aims are to maximize function while minimizing pain and disability. Few studies have explored patient-reported outcomes in the pediatric arthrogrypotic population, particularly concerning mobility. The aim of this study was to report scores for the Patient-Reported Outcome Measurement Information System (PROMIS) questionnaire for pediatric patients with arthrogryposis with regards to mobility, upper extremity (UE) function, pain interference, and peer relationships.

METHODS

A retrospective chart review of 76 patients with AMC aged 5 to 17 who completed the PROMIS questionnaire between January 1, 2017 to March 24, 2020 was performed. Results were collected for four domains: mobility, UE function, pain interference, and peer relationships. Outcomes were stratified by type of arthrogryposis: Amyoplasia (Am), Distal Arthrogryposis (DA), and Other Diagnoses (OD). Results of subjects with isolated upper or lower extremity involvement were compared with subjects with involvement of upper and/or lower extremities. Outcomes were correlated with history of surgical intervention.

RESULTS

Children with Am and OD demonstrated moderate impairment of mobility (average: 35.2 and 35.9, respectively), while those with DA reported only mild impairment (average: 44.9). UE function was severely impaired for children with Am (average: 23.0), moderately impaired for OD (average: 33.0), and mildly impaired for DA (average: 43.4). All patient groups reported normal ranges of pain interference, as well as good peer relationships. A moderate negative correlation between number of surgical interventions and mobility scores, and a weak negative correlation between number of surgeries and pain interference scores were found.

CONCLUSIONS

Children with AMC experience limited mobility and UE function, but normal levels of pain interference and good peer relationships. The average values provided in this study will serve as a baseline from which to evaluate the efficacy of both nonoperative and surgical interventions.

LEVEL OF EVIDENCE

Level II-prognostic study; retrospective study.

Bone densities and bone geometry in children and adolescents with arthrogryposis

OBJECTIVE

To describe bone densitometry results using lumbar spine dual-energy X-ray absorptiometry and forearm peripheral quantitative computed tomography (pQCT) in children with arthrogryposis multiplex congenita (AMC).

STUDY DESIGN

Prospective study.

RESULTS

Lumbar spine areal bone mineral density (BMD) was measured in 58 participants (mean age 6.8 years, range 1 month to 19.7 years; 26 males). The diagnostic subgroup was Amyoplasia in 27 participants, distal arthrogryposis (unclassified, n = 13; type 2A, n = 1; type 2B, n = 2; type 8, n = 2) in 18 patients, an unclassified form of arthrogryposis in 6 patients, and a syndromic form of arthrogryposis in 7 patients. The mean lumbar spine areal BMD was -0.4 (SD: 1.5) which was significantly below 0 (p < 0.05, one-sample t-test). The mean lumbar spine bone mineral apparent density z-score (+0.4 [SD: 1.4]), a measure that is largely independent of bone size, was not significantly different from 0 (P > 0.05). A subset of 22 patients aged 6 years or older (mean age 10.9 years, 11 males) had forearm pQCT analysis. Mean z-scores for trabecular and cortical volumetric BMD at the radius were similar to healthy controls. Radius periosteal bone circumference and bone mineral content were appropriate for height. These densitometric results did not differ between patients with Amyoplasia or individuals with other diagnoses.

CONCLUSIONS

Low areal BMD in children and adolescents with AMC reflects their smaller bone size rather than a specific bone mass deficit. These data do not suggest that children and adolescents with AMC in general require regular monitoring by bone densitometry unless there are specific clinical concerns.

A Telerehabilitation Intervention for Youths With Arthrogryposis Multiplex Congenita: Protocol for a Pilot Study

Background

Arthrogryposis multiplex congenita (AMC) is characterized by joint contractures present in at least two body areas. In addition to these contractures, individuals with AMC can have decreased muscle mass, leading to limitations in activities of daily living. Exercise has the potential to maintain or improve the range of motion and muscle strength. However, this type of intervention necessitates frequent follow ups that are currently difficult to provide for youths with AMC because they often live far from a specialized hospital. To overcome this distance challenge, telecommunication technologies can be used to deliver rehabilitation remotely, which is called telerehabilitation. The study protocol for one such type of rehabilitation will be presented in this paper.

Objective

This pilot study aims to (1) evaluate the feasibility of using telerehabilitation to provide a home exercise program for youths with AMC, and (2) assess the effectiveness of a home exercise program.

Methods

A total of 10 youths aged 8-21 years with AMC will be recruited. The intervention consists of a 12-week individualized home-based exercise program delivered remotely using telerehabilitation. At baseline, youths will complete the Physical Activity Questionnaire for Adolescents and the Pediatrics Outcomes Data Collection Instrument to assess pain, function, and level of physical activity. During the first telerehabilitation meeting, the rehabilitation therapists will measure range of motion using a virtual goniometer and assess the youth’s functional level. The therapists will then use the Goal Attainment Scale to set objectives and develop the individualized intervention. Follow ups will occur every 3 weeks to make sure exercises are performed safely and to progress the exercises when needed. At the end of the 12-week intervention, rehabilitation therapists will re-evaluate the youth using the same outcome measures as the initial evaluation. The youths will be asked to complete the same questionnaires, with the addition of questions about their satisfaction regarding the intervention. Nonparametric and descriptive statistics will be used to evaluate the feasibility and effectiveness.

Results

Ethics approval was obtained in October 2018. Recruitment and data collection started in January 2019 and was completed in May 2020.

Conclusions

This pilot study will help us learn how a large-scale project may work in practice to improve outcomes in physical activity, pain, and function, and goal attainment among youths with AMC, thus informing a future clinical trial.

International Registered Report Identifier (IRRID)

DERR1-10.2196/18688

Participation among Children with Arthrogryposis Multiplex Congenita: A Scoping Review

AIM

To explore what is currently known regarding participation among children and youth with arthrogryposis multiplex congenita (AMC) using empirical studies, gray literature, and YouTube videos. The secondary objectives included identifying activity types, outcome measures used, interventions provided, and barriers and facilitators to participation.

METHOD

Empirical studies and gray literature were searched through electronic databases and videos were searched on YouTube. Articles and videos pertaining to participation and youth with AMC were included by two reviewers. Data regarding activity types, location, outcomes measures, interventions, and barriers and facilitators to participation was extracted. Data was critically appraised using specific evaluation criteria.

RESULT

Eleven empirical studies, six gray literature articles and 71 videos met the inclusion criteria. The most common activity types reported in the empirical studies and YouTube videos were active-physical, social, and skill-based activities. Outcome measures included evaluations and questionnaires, none of which were designed to address participation. Interventions did not target participation although the environments could affect participation.

CONCLUSION

The paucity of research indicates a need for future studies of participation in this population. Interventions should target participation and address environmental barriers. Videos provide insight for clinicians, youth, and families to help promote participation in the natural environment.

Recessive mutations in SCYL2 cause a novel syndromic form of arthrogryposis in humans

Arthrogryposis multiplex congenita (AMC) is an important birth defect with a significant genetic contribution. Many syndromic forms of AMC have been described, but remain unsolved at the molecular level. In this report, we describe a novel syndromic form of AMC in two multiplex consanguineous families from Saudi Arabia and Oman. The phenotype is highly consistent, and comprises neurogenic arthrogryposis, microcephaly, brain malformation (absent corpus callosum), optic atrophy, limb fractures, profound global developmental delay, and early lethality. Whole-exome sequencing revealed a different homozygous truncating variant in SCYL2 in each of the two families. SCYL2 is a component of clathrin-coated vesicles, and deficiency of its mouse ortholog results in a severe neurological phenotype that largely recapitulates the phenotype observed in our patients. Our results suggest that severe neurogenic arthrogryposis with brain malformation is the human phenotypic consequence of SCYL2 loss of function mutations.

A review of the orthopedic interventions and functional outcomes among a cohort of 114 children with arthrogryposis multiplex congenita

PURPOSE

Arthrogryposis multiplex congenita (AMC) refers to a large heterogeneous group of conditions involving joint contractures in two or more different areas of the body. Contractures can lead to decreased range of motion and strength, and affect ambulation and autonomy. The aim of this study was to describe the orthopedic interventions and functional outcomes of a large cohort of children with AMC followed in a pediatric orthopedic center.

METHODS

A retrospective chart review of all children diagnosed with AMC followed at Shriners Hospital for Children - Canada (SHC) between January 1979 and July 2016 was conducted. One hundred twenty patients were identified, of whom six were excluded due to misdiagnosis or insufficient chart information. One hundred fourteen were retained. Patient demographics, AMC classification, comorbidities, operative and non-operative treatments received as well as community ambulation status, level of autonomy in self-care and transfers at latest follow-up were recorded.

RESULTS

There were 54 males and 60 females with a mean age at last clinic visit of 10 years 3 months. Amyoplasia and distal arthrogryposis (DA) were equally represented in our sample, 47 (41.2%) and 49 (43.0%) participants respectively, with the category Other comprising the remaining 18 (15.8%) participants. Children with DA had less involvement of the proximal joints than those in the two other groups. Contractures and deformities of the foot and ankle were the most prevalent, affecting 91.5% with Amyoplasia, 85.7% with DA and 83.3% in the Other category. Contractures of the shoulder and elbow were more common among individuals with Amyoplasia and those categorized Other than those with DA. In terms of walking ability, 98% of participants with DA were independent ambulators. Walking ability varied among the Other participants. Similarly, most children with DA were independent in self-care and transfers at the most recent follow-up.

CONCLUSION

The relatively large sample size of this study allowed for a better insight into the challenges associated with AMC management. These findings demonstrated the need for genetic testing to provide accurate diagnosis and classification, along with the use of standardized outcome tools to measure effectiveness of interventions. As AMC is rare, multi-site prospective studies are needed to improve research opportunities, develop functional measures specific to AMC and disseminate findings on a wider scale.

Pain among children and adults living with arthrogryposis multiplex congenita: A scoping review

Clinical interventions and research have mostly focused on the orthopedic and genetic outcomes of individuals with arthrogryposis multiplex congenita (AMC), and although pain has gained recognition as an important issue experienced by individuals with AMC, it has received little attention within the AMC literature. The aims of this scoping review were to describe the pain experiences of children and adults with AMC, to identify pain assessment tools and management techniques, and document the impact of pain on participation in everyday activities among children and adults with AMC. A search of the literature was conducted in four search engines and identified a total of 89 articles. Once study eligibility was reviewed, 21 studies met the selection criteria and were included in this review. Pain appears to be more commonly experienced in adults with AMC compared with children with AMC, with individuals having undergone multiple corrective procedures self-reporting pain more often. In adult populations, musculoskeletal chronic pain is a significant problem, resulting in restrictions in activities of daily living, mobility, and participation. Researchers and clinicians must agree on the use of validated measures appropriate for evaluating pain in AMC and the use of appropriate pain management techniques to relieve pain. Pediatric studies should focus on determining how commonly pain is experienced in infants, children, and adolescents with AMC. Pain in adults with AMC should be acknowledged to offer proper client-centered interventions throughout the lifespan.

Muscle and joint function in children living with arthrogryposis multiplex congenita: A scoping review

Arthrogryposis multiplex congenita (AMC) is characterized by congenital joint contractures present in two or more body areas. Lack of fetal movement is the underlying cause of AMC, which can lead to abnormal connective tissue surrounding the joint resulting in stiffness and muscle atrophy. Treatment aims at improving function and mobility through surgical and/or conservative interventions. A scoping review was conducted to explore the existing knowledge of the evaluation and treatment of muscle and joint function in children with AMC. Three search engines were included and identified 1,271 articles. Eighty-seven studies met the selection criteria and were included in this review. All included studies focused on joints, 30 of which also assessed the muscle. Assessment most often included the position of the contractures (n = 72), as well as range of motion (n = 66). Interventions to improve muscle and joint function were reported in 82 of the 87 papers and included surgery (n = 70) and conservative interventions (n = 74) with bony surgery (i.e., osteotomy) the most common surgery and rehabilitation the most common conservative intervention. Recurrences of contractures were mentioned in 46 of the 68 studies providing a follow-up. Future studies should use validated measures to assess muscle and joint function, and conservative interventions should be described in greater detail and to include a longer follow-up.

Rehabilitation needs of youth with arthrogryposis multiplex congenita: Perspectives from key stakeholders

Background: Arthrogryposis multiplex congenita is a term used to describe congenital contractures in at least two body parts with an overall prevalence of 1 in 3000 live births. It is often caused by lack of fetal movement in utero and presents as contractures of varying severity, which may affect the upper and lower extremities, the spine and jaw. Currently, no practice recommendations exist to inform best clinical practice for arthrogryposis multiplex congenita.Purpose: To identify the needs surrounding rehabilitation as experienced by youth with arthrogryposis multiplex congenita, caregivers, and clinicians and to propose solutions to develop family- and client-centred rehabilitation recommendations.Materials and methods: A modified experience-based co-design methodology was used where qualitative interviews were conducted with key stakeholders.Results: Twenty-seven participants completed the interviews and demographic information was collected where early-active rehabilitation began at birth in most cases and became less frequent through adolescence. Three overarching themes were determined for each stakeholder group.Conclusions: All participants reported that early-active rehabilitation is beneficial as it helps determine future treatments. Transition times and participation need to be at the center of interventions to ensure that the needs of youth with arthrogryposis multiplex congenita are being met. The development a condition-specific outcome-measure and rehabilitation practice recommendations will assist clinicians in addressing the needs of youth with arthrogryposis multiplex congenita.Implications for rehabilitationArthrogryposis multiplex congenita presents in at least two different areas of the body as multiple congenital contractures of varying severity which may affect the upper and lower extremities, spine and jaw.Youth with arthrogryposis multiplex congenita identified participation as an essential component of their life, however caregivers and clinicians did not emphasize this need.Gathering information from different stakeholders is important to ensure varying needs are addressed.Rehabilitation was reported to be beneficial from early childhood to late adolescence by youth, caregivers, and clinicians.Frequency of rehabilitation diminished over time, emphasizing the need for continued follow-up into adolescence.

Muscle-Bone Interactions in Pediatric Bone Diseases

PURPOSE

Here, we review the skeletal effects of pediatric muscle disorders as well as muscle impairment in pediatric bone disorders.

RECENT FINDINGS

When starting in utero, muscle disorders can lead to congenital multiple contractures. Pediatric-onset muscle weakness such as cerebral palsy, Duchenne muscular dystrophy, spinal muscular atrophy, or spina bifida typically are associated with small diameter of long-bone shafts, low density of metaphyseal bone, and increased fracture incidence in the lower extremities, in particular, the distal femur. Primary bone diseases can affect muscles through generic mechanisms, such as decreased physical activity or in disease-specific ways. For example, the collagen defect underlying the bone fragility of osteogenesis imperfecta may also affect muscle force generation or transmission. Transforming growth factor beta released from bone in Camurati Engelman disease may decrease muscle function.

FUTURE DIRECTIONS

Considering muscle-bone interactions does not only contribute to the understanding of musculoskeletal disorders but also can identify new targets for therapeutic interventions.

The importance of foetal movement for co-ordinated cartilage and bone development in utero : clinical consequences and potential for therapy

Construction of a functional skeleton is accomplished through co-ordination of the developmental processes of chondrogenesis, osteogenesis, and synovial joint formation. Infants whose movement in utero is reduced or restricted and who subsequently suffer from joint dysplasia (including joint contractures) and thin hypo-mineralised bones, demonstrate that embryonic movement is crucial for appropriate skeletogenesis. This has been confirmed in mouse, chick, and zebrafish animal models, where reduced or eliminated movement consistently yields similar malformations and which provide the possibility of experimentation to uncover the precise disturbances and the mechanisms by which movement impacts molecular regulation. Molecular genetic studies have shown the important roles played by cell communication signalling pathways, namely Wnt, Hedgehog, and transforming growth factor-beta/bone morphogenetic protein. These pathways regulate cell behaviours such as proliferation and differentiation to control maturation of the skeletal elements, and are affected when movement is altered. Cell contacts to the extra-cellular matrix as well as the cytoskeleton offer a means of mechanotransduction which could integrate mechanical cues with genetic regulation. Indeed, expression of cytoskeletal genes has been shown to be affected by immobilisation. In addition to furthering our understanding of a fundamental aspect of cell control and differentiation during development, research in this area is applicable to the engineering of stable skeletal tissues from stem cells, which relies on an understanding of developmental mechanisms including genetic and physical criteria. A deeper understanding of how movement affects skeletogenesis therefore has broader implications for regenerative therapeutics for injury or disease, as well as for optimisation of physical therapy regimes for individuals affected by skeletal abnormalities.

Cite this article: Bone Joint Res 2015;4:105–116

Amyoplasia revisited

Amyoplasia is a specific type and the most common form of arthrogryposis (multiple congenital contractures). It is a clinical diagnosis at this time. Care should be used making the diagnosis because of the implications for recurrence, natural history, associated anomalies, and both etiology and pathogenesis. We reviewed over 600 published reports and 2,500 individual records to identify the 560 individuals reported here. Affected limbs had characteristic positions with fatty-fibrous replacement of muscle. Upper limb involvement was usually characterized by extended elbows. Lower limbs were held in various positions at birth; however, equinovarus positioning of feet was almost always present. Symmetric involvement was common. Among 560 affected individuals, subtypes were identified: four-limb symmetric involvement (331/560 = 55.9%), severe involvement (41/560 = 7.3%), three-limb involvement (27/560 = 4.8%), upper limb only Amyoplasia (ULA; 94/560 = 16.8%), and lower limb only Amyoplasia (LLA; 25/560 = 15.5%). Discordant monozygotic twinning was increased, occurring in 6.6% (37/560; OR 10.9). A variety of additional anomalies were seen, attributed to apparent vascular compromise. Gastrointestinal vascular compromise-type anomalies were present in 9.1% (51/560), trunk muscle defects in another 2.7% (15/560), digit compromise in 12.1% (68/560), constriction rings in 4.3% (24/560), and perinatal long bone fractures in 10.5% (59/560). Although prenatal ultrasound became the standard of care in 1990, only about one quarter of affected pregnancies were diagnosed prenatally since 1990. Amyoplasia appears to be completely sporadic. Novel pathogenetic mechanisms for the congenital anomalies seen in Amyoplasia need to be identified.

Validation of the Brazilian version of the Pediatric Outcomes Data Collection Instrument: a cross-sectional evaluation in children and adolescents with juvenile idiopathic arthritis

BACKGROUND

There is a lack of health-related quality of life (HRQOL) questionnaires to evaluate pediatric musculoskeletal diseases in Brazil. The Pediatric Outcome Data Collection Instrument (PODCI) is widely used elsewhere for pediatric patients with musculoskeletal disorders, but it has not been fully validated in Brazil. Validation of the PODCI in the Brazilian Portuguese language is important to improve the assessment of pediatric patients with musculoskeletal diseases and to compare Brazilian study results with results from the international literature. This study aimed to analyze the test-re-test reliability and the convergent validity indicators for the quality of life scores obtained by application of the PODCI to children and adolescents with juvenile idiopathic arthritis (JIA).

METHODS

The PODCI underwent translation, transcultural adaptation, and field testing. Fifty-seven children and adolescents with JIA were administered the PODCI questionnaire. The Child Health Questionnaire - Parent Form 28 (CHQ PF-28) was used as the gold standard. Pain scales were employed, clinical examinations were performed, and laboratory inflammatory activity tests were conducted.

RESULTS

The three versions of the PODCI exhibited good internal consistency (Cronbach's alpha coefficient > 0.70), good reproducibility (p < 0.05), and good correlation compared with the gold standard (CHQ), as shown by a Spearman coefficient (Rho) > 0.40 (p < 0.05).

CONCLUSIONS

The PODCI was validated in patients with JIA in Brazil. This questionnaire was found to be valid, precise, and reliable. It can be successfully applied in research conducted by healthcare professionals who work with children and adolescents with musculoskeletal system disorders.